Proof of Authority (`hierachain/consensus/proof_of_authority.py`)

Overview

Proof of Authority (PoA) is an identity-based consensus protocol optimized for private blockchain networks or enterprise internal networks. Instead of solving complex cryptographic problems (like mining), PoA relies on a group of authorized nodes (Authorities) to validate and close blocks, achieving extremely fast transaction speeds with minimal latency.

How It Works

The protocol operates based on trust in the identity of participating nodes: 1. Node Identity: Each Authority is assigned an authority_id and a unique signing key pair. 2. Round-Robin Schedule: The system uses a sequential algorithm to determine which node has the right to create the next block based on the block index (BlockIndex % TotalAuthorities). 3. Signature Verification: Each new block must be signed by the designated Authority. Other nodes verify this signature before accepting the block into the ledger.

Key Features

Breakthrough Performance

Blocks are created instantly according to the configured cycle (block_interval), suitable for real-time response applications.
Identity Management

Supports flexible addition/removal of Authorities through the API, allowing network configuration changes without system downtime.
Absolute Integrity

Every block carries the digital signature of a verified organization, completely eliminating risks from anonymous or spoofed nodes.

Important Configuration Parameters

Parameter	Description	Default
`block_interval`	Minimum time between two blocks.	`10.0` seconds
`max_authorities`	Maximum number of Authority nodes in the network.	`100`
`require_signature`	Mandatory valid signature to accept a block.	`True`

Deployment Example

from hierachain.consensus import ProofOfAuthority

# Initialize PoA protocol
poa = ProofOfAuthority()

# Authorize nodes to participate in consensus
poa.add_authority("node_hq", metadata={"org": "Headquarters", "pubkey": "..."})
poa.add_authority("node_branch_1", metadata={"org": "Branch 01", "pubkey": "..."})

# Check block creation permission for current node
if poa.can_create_block("node_hq"):
    # Proceed to close block...
    pass

Advantages and Limitations

Advantages: Resource-efficient (no powerful CPU needed for mining), high throughput, transparent governance.
Limitations: Lower decentralization compared to BFT, only suitable for networks with a certain level of trust between members.

Proof of Authority (hierachain/consensus/proof_of_authority.py)